The field of the invention pertains to milking machine inflations, specifically to a device to position and maintain milking machine inflations lower on teats so as to maintain good milk flow.
For automatic milking, teat cups are fittable to the animal's teat for the removal of the milk from the udder through the teat. Teat cups conventionally used in most milking machines are formed from a flexible (usually rubber) inflation or liner emplaced inside a rigid shell to which an operating vacuum is supplied. The vacuum rhythmically pulsates from a milking to a resting stage, and thus stimulates the animal to let down the milk through the teat. Inflations used in teat cups of milking machines generally function as intended by milking out the teat completely in a timely manner.
There are some teats, however, that do not milk out well when the teat cup is attached. Because of the flexibility of the inflations and the massaging action during milking, the vacuum or suction tends to make the inflation move up on the teat. As the inflation head moves closer to the udder, the peripheral edge of the teat receiving opening tends to pinch the milk canal thus restricting the flow of milk. This is especially common with teats abnormally sized or shaped because of infection, injury, or inherited defects. The result is longer milking time and possible incomplete milkout which can lead to sore teat ends and possibly mastitis. A severe infection can even lead to permanent loss of milk production in that particular quarter.
This pinching effect is also particularly problematic with animals having a small milk or streak canal near the udder due to genetics or to an injury. A severe infection can even lead to permanent loss of milk production in that particular quarter of the udder.
To cull a dairy cow that is slow or difficult to milk because of teat abnormalities such as those mentioned above, is sometimes not an option. The cow may be a high producer and have excellent breeding qualities, therefore, being of too much value to the herd.
Although the need for a device to prevent pinching of the milk canal existed, no effective device was known. Thus the need for a device to positively position a milk inflation to prevent milk canal pinching, yet facilitate a steady and more rapid milkout of these special teats. Further, the need existed for a device to be easily attached and removed from an inflation.
Various forms of milking inflations and milking teat cups have been devised in an attempt to solve this problem. Examples of the known art are shown in the following United States Patents: U.S. Pat. No. 3,324,830 to McAndrew for an anti-creep adaptor for milking machine inflation; U.S. Pat. No. 3,485,212 to McAndrew for an anti-creep adaptor for milking machine inflation; U.S. Pat. No. 3,967,587 to Noorlander for a teat cup inflation; U.S. Pat. No. 4,269,143 to Erbach for a teat cup assembly; U.S. Pat. No. 4,315,480 to Noorlander for teat cups for milking machines; U.S. Pat. No. 4,372,250 to Larson for milking inflation; U.S. Pat. No. 4,425,872 to Mills for milking inflations; U.S. Pat. No. 5,007,378 to Larson for milking machine teat cup assembly; U.S. Pat. No. 5,161,482 to Griffin for automatic milking apparatus; U.S. Pat. No. 5,224,442 to Davies for milking apparatus; and United Kingdom Patent Number 117,307 to Robertson for improvements in milking machine teat cups; and United Kingdom Patent Number 2,272,826 to Grindal for teat cup liners.
The McAndrew '830 patent teaches an anti-creep adaptor for milking machine inflation that fits into the top of the inflation; the McAndrew '212 patent shows another anti-creep adaptor that fits into the top of the inflation that has inserts that may be screwed in; the Noorlander '587 patent describes an inflation to prevent teat slip in the teat cup, the teat opening of the inflation of the Noorlander '587 patent can have a corrugated edge; the Erbach patent teaches an inflation assembly that can be assembled without special tools and has a smooth flow surface to reduce flow back; the Noorlander '480 patent discusses a diaphragm to prevent the teat cup from falling off at the end of the milking process, the Larson patent '250 patent teaches an inflation that has a head end portion resists inward and outward deflection from its original position; the Mills patent shows two different sized barrel sections in the inflation to limit creep; the Larson '378 patent describes a liner cuff with an annular sleeve; the Griffin patent shows a regulator device which maintains the teat cup at atmospheric pressure; the Davies patent teaches an inflation with a reduced tendency to twist; the United Kingdom patent to Robertson discusses a lengthening ring fitting into and for lengthening the inflation for a long teat; and the United Kingdom patent to Grindal shows a teat cup liner with an upper and a lower section adapted to encircle the teat.
Although some of these patents deal with anti-creep of the inflation, none describe an easily attachable and removable device that fits over the outside of the inflation head.